The present invention relates generally to electrical connector devices, and more specifically to connectors for use in high data rate applications.
Current xe2x80x9cbox levelxe2x80x9d interconnect and cabling technologies utilized by original equipment manufacturer""s are driving overall system level enclosures to be smaller while increasing electrical performance of these same devices. Various requirements arise in order to facilitate the increased electrical performance of these devices. For instance, it is more critical to use highly reliable discrete wire termination methods, which are the processes for attaching the end of a line, channel or circuit to an electrical contact. It is desirable to have the option of logic (e.g., a printed circuit board) and discrete wire termination methods inside the same cabling medium. It is common for form factor requirements to drive industry standard design point data rates past intended design points. For example, Very High Density Cable Interconnect (VHDCI) connector devices designed for transmitting 40 MHz data rates actually carrying mission critical data at over 2 GHz. Of course, it is advantageous if interconnecting systems are compatible with legacy and current technologies. All of these requirements require special manufacturing processes combined with small form factor assembly and packaging methodologies. The current available industry solutions limit the ability in solving these issues cost effectively.
An important aspect of technologies for interconnecting electrical cabling involves terminating the cabling at a connector device. Current technologies from terminating cabling include insulation displacement contact (IDC), the use of printed circuit boards, solder termination, and welded or xe2x80x9cdirect attachxe2x80x9d methods. Each of these current technologies have different characteristics, which will now be briefly explained.
IDC involves attaching wires to the electrical interconnects of a connector device by placing an insulated wire between two metal prongs, which also serve as electrical contacts. The two metal prongs cut through the insulating material and at the same time make electrical contact with the conductive wire. The electrical performance of systems utilizing IDC is limited because the skew of each wire is difficult to control. The skew is the amount of misalignment between each wire and the interconnect (or contact lead) to which it is attached. Skew causes inconsistencies in the amount of contact formed between each of the wires and a respective interconnect. The variations in the amount of contact area is a critical problem in high transmission rate applications because it disrupts the timing of the finely synchronized signals in each of the wires. Therefore, IDC is generally a lesser-preferred method for terminating cabling for critical data applications.
Printed circuit boards are used to terminate cabling by connecting PCB""s to electrical interconnects and soldering discrete wires to the PCB. In this manner, the PCB""s are utilized as an intermediary connecting medium and are sometimes referred to as xe2x80x9cinterposer cards.xe2x80x9d The PCB method introduces the additional discrete wire-to-interconnect termination point, which can cause further reliability and quality problems. The PCB itself also adds the cost of an additional component. PCB""s actually provide some ability to improve electrical performance, for example, the embedded wire traces allow for the control of the wire layout at the PCB. However, problems arise in high frequency applications. Also, in general, the data frequency range for PCB connected systems are limited at high end, which is typically around 1 GHz.
Soldered termination involves soldering discrete wires directly to an electrical interconnect. The effectiveness of solder termination of fine pitch contacts in existing designs is limited by the ability of operators or processes to solder with a sufficient amount of precision. This naturally leads to reliability and quality problems. Additionally, material characteristics of the bond between cabling, interconnects and solder limit the performance of systems to data frequency ranges of approximately 1.2 GHz. Furthermore, current design points limit wire management options in small form factors, and electrical issues, such as skew, are virtually unsolvable at high frequencies.
Welded or xe2x80x9cdirect attachxe2x80x9d methods involve welding wires directly to a contact surface. Skew is hard to control in welding methods due to the lack of discrete wire management features and therefore, electrical performance of the electrical system is limited. It is also very difficult to obtain consistent repeatability in welding production. Auto-indexing features of current weld tools tend to limit throughput rates. Typically, connector designs consist of multiple rows within a single housing. This usually causes problems in manufacturing since positive and negative weld plates/heads must be used. Fixturing this type of application in small form factors such as VHDCI is extremely costly.
In view of the foregoing, a low cost interconnection device capable of reliably carrying high data rates would be desirable.
The present invention is directed to a small form factor connector device that can reliably carry high data rates and which can be implemented at a low cost. The disclosed connector device can be adopted across multiple interconnect platforms including current, legacy, or yet to be defined form factors. The device disclosed is modular in its approach, offers multiple termination mediums, and can be used in a variety of electrical packaging applications. The connector device ensures a high degree of wire position control through the use of wire retention combs and/or registration holes. The wire retention combs grip the discrete wires and the registration holes secure the ends of the exposed wires such that a stable and precise connection between the wires and the electrical contact leads of the device can be maintained. Each of these features, alone or in combination, thereby substantially reduces skew between wires and electrical interconnects of a connection device and allows for successful signal transmission at high frequencies. In alternative embodiments of the connector device, one surface of the contact leads are designed to connect with discrete wires and an opposite surface of the contact leads are designed to connect to an electronic device card. In some embodiments of the present invention, the connector device is formed of two substantially identical components that are attached to each other.
One aspect of the present invention relates to an electrical connector component that includes a support block and a plurality of contact leads. The plurality of contact leads are supported by the support block and each of the contact leads have a first connection portion suitable for making contact with an external connector device, a second connection portion suitable for making contact with electrical wires, and a third connection portion suitable for making contact with traces on an electrical device. The second connection portion of the contact leads have a longitudinal axis and the contact leads have a curved configuration such that the third connection portion of the contact leads are offset from the longitudinal axis of the second connection portions. The second and third connection portions of the contact leads form a leaf spring configuration.
These and other features and advantages of the present invention will be presented in more detail in the following specification of the invention and the accompanying figures, which illustrate by way of example the principles of the invention.